The Product Key you're entering might not be the actual one. True, there is
only one; but sometimes other Serial Numbers (for licensing, shipping codes,
and copyright) might be mistaken for the actual Product Key. It might be on
your Owners Manual, if you received one with the product, the actual CD
itself. If you know this one is correct, Microsoft Knowledge Base (KB
Articles) or email support, might help you to confirm you have it, cost free.
If you purchased the product through retail, or a Third Party manufacture, I
hope they might also help you to locate the it, cost free.

"Carol R." wrote:

I have a product key on the back of the CD box, but when I type it in and try
to continue, I get a message asking me to verify the number. I did verify the
number, but I keep getting the same message. Is there any quick fix? I know I
can call Microsoft support, but it galls me to have to use one of my two free
calls because of a product key they got wrong! Thanks.